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a(n) = Sum_{k=0..n} C(2*n-2*k,n-k)^2 * C(2*n,k)^2.
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%I #10 Jun 22 2022 11:31:16

%S 1,8,136,2996,76168,2121808,62886484,1947164948,62250464648,

%T 2038917457664,68056394358736,2306354482651568,79138758509239636,

%U 2743929765899780336,95983445574557632948,3383168407446955236196,120039826640626408744328

%N a(n) = Sum_{k=0..n} C(2*n-2*k,n-k)^2 * C(2*n,k)^2.

%D There's an erroneous assertion (caused by a typographical error) in the first printing of M. Petkovsek et al., "A=B", Peters, p. ix. that this is the same as A036917; it is not.

%t Table[Sum[Binomial[2n-2k,n-k]^2 Binomial[2n,k]^2,{k,0,n}],{n,0,20}] (* _Harvey P. Dale_, May 31 2015 *)

%K nonn

%O 0,2

%A _N. J. A. Sloane_